Interactive input systems that allow users to inject input into an application program using an active pointer (e.g. a pointer that emits light, sound or other signal), a passive pointer (e.g. a finger, cylinder or other object) or other suitable input device such as for example, a mouse or trackball, are well known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001 assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the entire disclosures of which are incorporated by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; tablet and laptop personal computers (PCs); personal digital assistants (PDAs) and other handheld devices; and other similar devices.
Above-incorporated U.S. Pat. No. 6,803,906 to Morrison et al. discloses a touch system that employs machine vision to detect pointer interaction with a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its corners. The digital cameras have overlapping fields of view that encompass and look generally across the touch surface. The digital cameras acquire images looking across the touch surface from different vantages and generate image data. Image data acquired by the digital cameras is processed by on-board digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y) coordinates relative to the touch surface using triangulation. The pointer coordinates are conveyed to a computer executing one or more application programs. The computer uses the pointer coordinates to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of application programs executed by the computer.
U.S. Pat. No. 6,972,401 to Akitt et al. assigned to SMART Technologies ULC, the disclosure of which is incorporated herein by reference in its entirety, discloses an illuminated bezel for use in a touch system such as that disclosed in above-incorporated U.S. Pat. No. 6,803,906 to Morrison et al. The illuminated bezel comprises infrared (IR) light emitting diodes (LEDs) that project infrared light onto diffusers. The diffusers in turn, diffuse the infrared light so that the intensity of backlighting provided over the touch surface by the illuminated bezel is generally even across the surfaces of the diffusers. As a result, the backlight illumination provided by the bezel appears generally continuous to the digital cameras. Although this illuminated bezel works very well, it adds cost to the touch system.
U.S. Patent Publication Application No. 2011/0242060 to McGibney et al., entitled “INTERACTIVE INPUT SYSTEM AND INFORMATION INPUT METHOD THEREFOR”, filed Apr. 1, 2010, assigned to SMART Technologies ULC, the disclosure of which is incorporated herein by reference in its entirety, discloses an interactive input system comprising at least one imaging assembly having a field of view looking into a region of interest and capturing image frames and processing structure in communication with the at least one imaging assembly. When a pointer exists in captured image frames, the processing structure demodulates the captured image frames to determine frequency components thereof and examines the frequency components to determine at least one attribute of the pointer.
U.S. Patent Application Publication No. 2011/0242006 to Thompson et al., filed on Apr. 1, 2010, entitled “INTERACTIVE INPUT SYSTEM AND PEN TOOL THEREFOR”, and assigned to SMART Technologies ULC, the disclosure of which is incorporated herein by reference in its entirety, discloses a pen tool for use with a machine vision interactive input system comprising an elongate body and a tip arrangement at one end of the body. An end surface of the body at least partially about the tip arrangement carries light reflective material that is visible to at least one imaging assembly of the interactive input system when the pen tool is angled.
U.S. Pat. No. 6,823,481 to Takekawa discloses a method and apparatus for preventing misdetection of coordinates of a pointing instrument. A coordinate input/detection device compares a waveform of a signal corresponding to intensity distribution of rays received from a coordinate input area by a light-receiving unit and a standard waveform at fixed timing. If the waveform is not equal to the standard waveform, the coordinate input/detection device determines that an installation position of the light-receiving unit is off a correct position because of shock or vibration. A new standard waveform is obtained and stored in a storage unit, thereby setting the waveform of the signal corresponding to the intensity distribution of rays received by the light-receiving unit located at an incorrect position as the standard waveform.
U.S. Pat. Nos. 7,202,860 and 7,414,617 to Ogawa disclose a coordinate input device that includes a pair of cameras positioned in an upper left position and an upper right position of a display screen of a monitor lying close to a plane extending from the display screen of the monitor and views both a side face of an object in contact with a position on the display screen and a predetermined desktop coordinate detection area to capture the image of the object within the field of view. The coordinate input device also includes a control circuit which calculates the coordinate value of a pointing tool, pointing to a position within a coordinate detection field, based on video signals output from the pair of cameras, and transfers the coordinate value to a program of a computer.
U.S. Pat. No. 6,567,078 to Ogawa discloses a handwriting communication system, a handwriting input device and a handwriting display device used in the system, which can communicate by handwriting among a plurality of computers connected via a network. The communication system includes a handwriting input device which is provided at a transmitting side for inputting the handwriting into a transmitting side computer, and a handwriting display device which is provided at a receiving side for displaying the handwriting based on information transmitted from the transmitting side to a receiving side computer. The system transmits only a contiguous image around the handwritten portion, which reduces the communication volume compared to transmitting the whole image, and which makes the real time transmission and reception of handwriting trace possible.
U.S. Pat. No. 6,441,362 to Ogawa discloses an optical digitizer for determining a position of a pointing object projecting a light and being disposed on a coordinate plane. In the optical digitizer, a detector is disposed on a periphery of the coordinate plane and has a view field covering the coordinate plane for receiving the light projected from the pointing object and for converting the received light into an electric signal. A processor is provided for processing the electric signal fed from the detector to compute coordinates representing the position of the pointing object. A collimator is disposed to limit the view field of the detector below a predetermined height relative to the coordinate plane such that through the limited view field the detector can receive only a parallel component of the light which is projected from the pointing object substantially in parallel to the coordinate plane. A shield is disposed to enclose the periphery of the coordinate plane to block noise light other than the projected light from entering into the limited view field of the detector.
Improvements are generally desired. It is therefore an object of the present invention at least to provide a novel interactive input system and a pen tool therefor.